53° 



A. G. LEONARD 



The following section is exposed in the valley of Hell Creek: 



Feet 



7. Shale and sandstone, light gray and yellow, containing beds of coal 



2 to 11 feet thick, and also many plant remains. Fort Union ... 115 



6. Shale and sandstone, similar in appearance to No. 4, but contains 



no dinosaur bones 100 



5. Coal bed, persistent, has been traced a distance of 25 miles 6 



4. Shale and sandstone with prevailing dark gray color; contains 

 many brown, carbonaceous layers and some beds of coal. Con- 

 tained in this member are two fairly persistent sandstone horizons 

 from 15 to 20 feet thick, and with 30 to 40 feet of shale 

 between. These sandstones contain many large brown sand- 

 stone concretions . 210-260 



3. Sandstone, the basal member of the Lance formation. Coarse- 

 grained and rather soft; characterized by its massiveness, irreg- 

 ularity of bedding, the great number of large sandstone concre- 

 tions, and its cross-lamination. Yellow and brown in color .... 100 



2. Shale, more or less sandy, with some sandstone, light gray to buff. 



Fox Hills 100 



1. Shale, dark gray, with fossiliferous calcareous concretions near the 



top. Pierre. Exposed above creek 150 



Nos. 3 and 4 of the above section, which belong to the Lance 

 formation, have yielded many dinosaur bones, including Tricera- 

 tops, Trachodon, and Tyrannosaurus ; also the remains of Campso- 

 saurus, crocodiles, and turtles, together with a few mammal teeth. 

 Plant remains are rare in this region, but Mr. Brown found the 

 following associated with the skeleton of a dinosaur: 1 



Sequoia Nordenskioldii Heer. Populus amblyrhyncha Ward. 



Taxodium occidentale Newb. Quercus sp. 



Ginkgo adiantoidis (Ung.) Heer. Ficus artocarpoides Lesq. 



Populus cuneata Newb. Sapindus afhnis Newb. 



A large number of invertebrates were also secured from the 

 Lance beds, including many species of Unios. 



The age of No. 6 of the above section, which corresponds to 

 Barnum Brown's "lignite beds," is uncertain since it contains 

 almost no fossils. Largely on the basis of the lack of dinosaur 

 bones in this member, Mr. Brown separates it from his Hell Creek 

 beds and regards it as probably Fort Union. He correlates it, 

 however, and correctly, with the 400 feet of strata exposed at 



1 Proc. Wash. Acad. Sri., XI, No. 3, p. 1S5. 



